As told by Cinched:

Ziva and I were watching an old detective movie on television, and she began to make disparaging comments about how fake she felt the bondage in the movie was. Sensing an opportunity, I made a simple bet with her: If she could escape an identical tie, I'd take her shopping. She eagerly agreed, and soon realized that when you are bound hand and foot, your limbs fused together by unforgiving rope and your mouth packed with hard rubber that allows plenty of drool to escape (but no recognizable words), escape it far trickier than it looks! She thrashed and struggled...

As told by Cinched:

Ziva and I were watching an old detective movie on television, and she began to make disparaging comments about how fake she felt the bondage in the movie was. Sensing an opportunity, I made a simple bet with her: If she could escape an identical tie, I'd take her shopping. She eagerly agreed, and soon realized that when you are bound hand and foot, your limbs fused together by unforgiving rope and your mouth packed with hard rubber that allows plenty of drool to escape (but no recognizable words), escape it far trickier than it looks! She thrashed and struggled, squirmed and strained, gurgling her displeasure all the while, but once she was but into a modified ball tie, she know she had lost the bet. Too bad she did not ask me what the penalty for losing would be! Oh well, she'll find out soon!